Ready to buy the new iPhone? With several wireless carriers to choose from, now's a good time to review their differences. Here's a comparison of your options so you can pick the best plan.

We recently compared the big four wireless providers in general, but now we'll focus on just those who are offering the new iPhone: AT&T, Sprint, and Verizon. Two prepaid carriers, Cricket and Virgin Mobile, who currently offer the iPhone 4S may also get the iPhone 5—but probably not any time soon since that hasn't been announced yet. Still, we're including Cricket and Virgin Mobile (both of which run on the Sprint network) below for your future reference. Let's take a look at costs and performance.

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Phone Price and Data Rates

In terms of the device itself, the iPhone will cost the same at AT&T, Sprint, and Verizon: $199 for 16GB, $299 for 32GB, and $399 for 64GB—with a new two-year contract.

(If Cricket and Virgin Mobile get the iPhone 5, their prices will likely be the same as those offered for the iPhone 4S: for the 16GB model, that's $500 at Cricket and $650 on Virgin Mobile. The prepaid carriers, however, don't require any contract, so there are no early termination fees, and even though you pay more for the phone upfront, the lower plan rates and lack of silly activation fees on Cricket and Virgin Mobile could offset the phone price in the long run. For example, you save about $40 a month on Virgin Mobile for unlimited* everything compared to Sprint; over the course of two years that $480 $960 savings would more than cover the premium price for the phone.)

The data and calling plans vary quite a bit among the providers. AT&T and Verizon have "shared data plans"—a bundle of data to be spread across your devices. This could be cost-effective if you (and your family) use the iPhone with several other devices, but generally they're more expensive than the unlimited data plans on Sprint, Cricket, and Virgin Mobile.

Below are two pricing comparison charts (click to see the charts in their entirety). In essence:

Only truly unlimited data iPhone plan: Sprint is the iPhone carrier of choice if you want truly unlimited data—no throttling or caps.

Toss up if you're choosing between AT&T or Verizon on price alone: AT&T and Verizon pricing are about the same. AT&T gives you 3GB of data on one iPhone with unlimited talk and text, while Verizon gives you 2GB for $20 less a month. If you add more iPhones or smartphones to your plan, Verizon is $5/month cheaper than AT&T for each additional smartphone.

Cheapest minutes plan: Cricket has the cheapest minutes-based calling plans: $25 for 300 minutes of talk, with unlimited* texting and data. Or you can get 1,000 minutes for $35 a month.

Cheapest unlimited plan: Virgin Mobile has the best deal for unlimited* everything: $55 a month

On the shared/family plan side, AT&T and Verizon are cheaper than Sprint for just two smartphones up to 4GB on the shared plans ($150 for two smartphones with 4GB shared versus $190 on Sprint). Assuming the iPhone will come to prepaid providers, Virgin Mobile would also come out on top for unlimited* everything for two smartphones—just $110 a month (Cricket doesn't have unlimited data).

*Unlimited in theory, but throttled after a little more than 2GB of usage.

Performance and Coverage

Pricing isn't everything, though. Most important, you want to make sure you get good coverage, call quality, and data performance for your iPhone in your area. To check that out, consult the carriers' coverage maps and sites like SignalMap to find out if you can get a strong and reliable signal. (DeadCellZones and OpenSignalMaps are two other useful resources, but they don't seem to include Cricket or Virgin Mobile. Also note that Cricket's iPhone 4S coverage is only in certain cities, so the iPhone 5 might not be available on Cricket in your area.)

Verizon has the broadest 4G LTE network, with 300 markets across the US and coverage for over 75% of Americans, according to GottaBeMobile. AT&T has fewer than 100 4G LTE markets and Sprint has less than 50, though all of these networks promise to expand their 4G LTE coverage.

Verizon also seems to score best in all the third-party tests for network quality and 4G speeds (J.D. Power named it highest in network quality, PCWorld said it was tops for 4G uploads, and PCMagazine said it was fastest). AT&T fared well for 4G downloads, though, in PCWorld's tests.

Unfortunately, these tests didn't include Cricket or Virgin Mobile for comparison, probably because they're in limited market areas. However, because both services run on Sprint's network, you could look at the Sprint test results to compare (also unfortunately, Sprint doesn't perform too well according to those tests. I can confirm that at least in the NYC suburbs, Virgin Mobile data is horribly slow.)

Other Considerations

Beyond pricing and performance, you should also take into account customer service. In our previous wireless carriers comparison, we found that two studies named Verizon tops for overall customer service (Consumer Reports said AT&T customers were least satisfied).

Finally, one more option you might consider is getting an unlocked iPhone when it becomes available on T-Mobile. This wireless provider is one of the few who aren't getting the iPhone, but unlocked iPhones can run on its network—with many caveats, according to CNET. First, T-Mobile can only accept phones from AT&T, because of wireless spectrum differences with Verizon and Sprint. Second, iPhones will run slower on T-Mobile's network than other 4G smartphones because the iPhone's HSPA+ modem only goes up to 14.4 megabits per second, while T-Mobile is upgrading its 4G network to HSPA+ 42 (with 42 megabits per second speeds). Despite the limitations, T-Mobile would be a good alternative if you're on a budget, especially with the new $90 plans with truly unlimited data ($10 cheaper than Sprint). Unlocked iPhones make sense in certain situations, such as international travel.

The best iPhone 5 carrier for you depends mostly on what kind of coverage and performance you have in your area and how much data you expect to use. Take the above into consideration before you make your decision.